use axum::http::HeaderValue;
use axum::{
    Router,
    body::Body,
    extract::{Path, State},
    http::{StatusCode, Uri, header},
    response::{IntoResponse, Response},
    routing::get,
};
use std::net::SocketAddr;
use std::path::PathBuf;
use tokio::{fs, sync::broadcast};
use tower_http::services::ServeDir;
use tracing::{info, warn};

#[derive(Clone)]
struct AppState {
    website_root: PathBuf,
    shutdown_tx: broadcast::Sender<()>,
}

async fn git_pull(State(state): State<AppState>) -> impl IntoResponse {
    let fetch = tokio::process::Command::new("git")
        .args(["fetch", "origin"])
        .current_dir(&state.website_root)
        .output()
        .await;

    let reset = tokio::process::Command::new("git")
        .args(["reset", "--hard", "origin/main"])
        .current_dir(&state.website_root)
        .output()
        .await;

    match (fetch, reset) {
        (Ok(fetch_out), Ok(reset_out)) => {
            let success = fetch_out.status.success() && reset_out.status.success();

            let fetch_stdout = String::from_utf8_lossy(&fetch_out.stdout);
            let fetch_stderr = String::from_utf8_lossy(&fetch_out.stderr);

            let reset_stdout = String::from_utf8_lossy(&reset_out.stdout);
            let reset_stderr = String::from_utf8_lossy(&reset_out.stderr);

            if !fetch_stdout.trim().is_empty() {
                info!("git fetch stdout: {}", fetch_stdout.trim());
            }
            if !fetch_stderr.trim().is_empty() {
                warn!("git fetch stderr: {}", fetch_stderr.trim());
            }

            if !reset_stdout.trim().is_empty() {
                info!("git reset stdout: {}", reset_stdout.trim());
            }
            if !reset_stderr.trim().is_empty() {
                warn!("git reset stderr: {}", reset_stderr.trim());
            }

            let body = format!(
                "status: {}\n\n--- fetch ---\nstdout:\n{}\nstderr:\n{}\n\n--- reset ---\nstdout:\n{}\nstderr:\n{}",
                if success { "ok" } else { "error" },
                fetch_stdout,
                fetch_stderr,
                reset_stdout,
                reset_stderr
            );

            (
                if success {
                    StatusCode::OK
                } else {
                    StatusCode::INTERNAL_SERVER_ERROR
                },
                body,
            )
        }

        (Err(fetch_err), Ok(_)) => {
            warn!("failed to run git fetch: {}", fetch_err);
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                format!("git fetch failed: {}", fetch_err),
            )
        }

        (Ok(_), Err(reset_err)) => {
            warn!("failed to run git reset: {}", reset_err);
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                format!("git reset failed: {}", reset_err),
            )
        }

        (Err(fetch_err), Err(reset_err)) => {
            warn!("failed to run git fetch: {}", fetch_err);
            warn!("failed to run git reset: {}", reset_err);
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                format!(
                    "both commands failed:\nfetch: {}\nreset: {}",
                    fetch_err, reset_err
                ),
            )
        }
    }
}

async fn shutdown(State(state): State<AppState>) -> StatusCode {
    let _ = state.shutdown_tx.send(());
    StatusCode::OK
}

#[tokio::main]
async fn main() {
    tracing_subscriber::fmt::init();

    let website_root = PathBuf::from("../website");
    let (shutdown_tx, _) = broadcast::channel(1);
    let state = AppState {
        website_root: website_root.clone(),
        shutdown_tx: shutdown_tx.clone(),
    };

    let app = Router::new()
        .route("/", get(serve_index))
        .route("/post/{file}", get(serve_post_page))
        .route("/api/backdrops.json", get(serve_backdrops))
        .route("/api/staff.json", get(serve_staff))
        .route("/api/teams.json", get(serve_teams))
        .route("/api/posts.json", get(serve_posts))
        .route("/api/post/{file}", get(serve_post_md))
        .route("/api/update", get(git_pull)) // I know this is risky
        .route("/api/shutdown", get(shutdown)) // once propper auth & workflows exist this should be removed
        .route("/directs/{name}", get(serve_direct))
        .nest_service("/assets", ServeDir::new(website_root.join("assets")))
        .nest_service("/posts", ServeDir::new(website_root.join("posts")))
        .fallback(get(serve_static))
        .with_state(state.clone());

    let mut shutdown_rx = shutdown_tx.subscribe();
    let http_handle = tokio::spawn(async move {
        let addr = SocketAddr::from(([0, 0, 0, 0], 1200));
        info!("HTTP server listening on {}", addr);

        let listener = tokio::net::TcpListener::bind(addr).await.unwrap();

        axum::serve(listener, app)
            .with_graceful_shutdown(async move {
                let _ = shutdown_rx.recv().await;
                info!("Shutdown signal received");
            })
            .await
            .unwrap();
    });

    http_handle.await.unwrap();
}

async fn serve_index(State(state): State<AppState>) -> impl IntoResponse {
    info!("Serving index.html");
    serve_file(state.website_root.join("index.html")).await
}

async fn serve_post_page(
    State(state): State<AppState>,
    Path(_file): Path<String>,
) -> impl IntoResponse {
    info!("Serving post.html");
    serve_file(state.website_root.join("post.html")).await
}

async fn serve_backdrops(State(state): State<AppState>) -> impl IntoResponse {
    info!("Serving backdrops.json");
    serve_file(state.website_root.join("api/backdrops.json")).await
}

async fn serve_staff(State(state): State<AppState>) -> impl IntoResponse {
    info!("Serving staff.json");
    serve_file(state.website_root.join("api/staff.json")).await
}

async fn serve_teams(State(state): State<AppState>) -> impl IntoResponse {
    info!("Serving teams.json");
    serve_file(state.website_root.join("api/teams.json")).await
}

async fn serve_posts(State(state): State<AppState>) -> impl IntoResponse {
    info!("Serving posts.json");
    serve_file(state.website_root.join("api/posts.json")).await
}

async fn serve_post_md(
    State(state): State<AppState>,
    Path(file): Path<String>,
) -> impl IntoResponse {
    info!("Serving {}", file);
    let path = state.website_root.join("posts").join(&file);
    if path.exists() {
        let content = fs::read_to_string(path).await.unwrap_or_default();
        Response::builder()
            .header(header::CONTENT_TYPE, "text/markdown; charset=utf-8")
            .body(Body::from(content))
            .unwrap()
    } else {
        StatusCode::NOT_FOUND.into_response()
    }
}

async fn serve_static(uri: Uri, State(state): State<AppState>) -> impl IntoResponse {
    let path = uri.path().trim_start_matches('/');
    let file_path = state.website_root.join(path);
    info!("Serving static file, {}", path);

    if file_path.exists() && file_path.is_file() {
        serve_file(file_path).await
    } else {
        StatusCode::NOT_FOUND.into_response()
    }
}

async fn serve_file(path: PathBuf) -> Response {
    if !path.exists() {
        return StatusCode::NOT_FOUND.into_response();
    }

    let content = match fs::read(&path).await {
        Ok(c) => c,
        Err(_) => return StatusCode::INTERNAL_SERVER_ERROR.into_response(),
    };

    let mime = match path.extension().and_then(|e| e.to_str()) {
        Some("html") => "text/html",
        Some("css") => "text/css",
        Some("js") => "application/javascript",
        Some("json") => "application/json",
        Some("png") => "image/png",
        Some("jpg") | Some("jpeg") => "image/jpeg",
        Some("mp4") => "video/mp4",
        Some("md") => "text/markdown; charset=utf-8",
        _ => "application/octet-stream",
    };

    Response::builder()
        .header(header::CONTENT_TYPE, mime)
        .body(Body::from(content))
        .unwrap()
}

async fn serve_direct(
    State(state): State<AppState>,
    Path(name): Path<String>,
) -> impl IntoResponse {
    info!("Serving redirect {}", name);
    if name.contains('/') || name.contains('\\') || name.starts_with('.') {
        return StatusCode::BAD_REQUEST.into_response();
    }

    let path = state.website_root.join("directs").join(&name);

    if !path.exists() || !path.is_file() {
        return StatusCode::NOT_FOUND.into_response();
    }

    let content = match fs::read_to_string(&path).await {
        Ok(c) => c.trim().to_string(),
        Err(_) => return StatusCode::INTERNAL_SERVER_ERROR.into_response(),
    };

    if content.is_empty() {
        return StatusCode::NO_CONTENT.into_response();
    }

    if !content.starts_with("http://") && !content.starts_with("https://") {
        warn!("invalid redirect target in {:?}: {}", path, content);
        return StatusCode::INTERNAL_SERVER_ERROR.into_response();
    }

    Response::builder()
        .status(StatusCode::FOUND) // 302 redirect
        .header(header::LOCATION, HeaderValue::from_str(&content).unwrap())
        .body(Body::empty())
        .unwrap()
}